This invention relates to a battery charging device installing structure for an outboard motor and more particularly to an improved mounting and cooling arrangement for the rectifier of an outboard motor battery charging system.
It is well known with outboard motors, particularly those of the large displacement type, to employ a separate battery which battery is charged by an alternator which may form a portion of the magneto ignition system for the engine. Because of the alternating input current from the charging device, it is necessary to employ a rectifier for converting the alternating current into direct current to charge the battery. Frequently, a voltage regulator is also employed in conjunction with the rectifier. When used herein in both the specification and claims, the term "rectifier" is used generically so as to cover a rectifier per se or a rectifier regulator.
Obviously, the rectifier becomes heated in its operation. As larger alternators are employed, the amount of heat generated by the rectifier increases significantly. It has been the practice to provide an arrangement for cooling the rectifier in outboard motor applications. This may be done by providing either cooling fins on the rectifier for air cooling or by placing the rectifier so that it will be in contact with the engine water cooling system and water cooled. However, both of these constructions have disadvantages.
As the power output becomes larger, the dimension of the cooling fins also becomes larger. Quite obviously there is not adequate space in conventional outboard motors to accommodate such large finned rectifiers. In addition, the increase in the amount of finning can in some events actually interfere with the amount of cooling.
Where the rectifier is water cooled, on the other hand, obvious corrosion problems can exist, particularly when operating in marine environments. As corrosion builds up on the rectifier outer surfaces, the heat transmission ability becomes reduced and overheating and eventual destruction of the rectifier can be a problem.
It is, therefore, a principal object of this invention to provide an improved rectifier and mounting arrangement for an outboard motor wherein the rectifier will be cooled but no special cooling construction of the rectifier per se or involvement with the engine cooling system is required.
It is a further object of this invention to provide an improved, simplified and highly effective arrangement for cooling a rectifier in an outboard motor battery charging system.